Since the popularization of suburban living, people have become very involved and concerned with the care and appearance of their lawns. Industries have been devoted to the continuous research and development of new lawn care products, including underground sprinkler systems. Typically, these systems involve a number of special sprinkler heads located and buried flush with the ground surface. The sprinkler heads are connected together by buried piping and linked to a valve control box. When a large area is to be watered there may be several individual zones operated separately through the valve control box. Eventually the entire system operates from a main control drawing water from a main water supply line located within a building structure. Initialization of any one zone, or all zones, begins with a valve opening and increased water flow to that zone. Sprinkler heads pop-up to release the water, returning to their flush position when water pressure is reduced below a certain level. Such a sprinkler system is detailed in U.S. Pat. No. 5,004,157 to Martell. To the extent the information in the Martell reference is helpful in understanding the general features of the present invention it is hereby incorporated by reference.
Unfortunately, due to the possibility of freezing water and severe damage to the system in many areas of the U.S. and foreign countries, these systems must be seasonally relieved of their residual water--the water which remains in the system after a watering cycle--before the onset of the cold winter months. This is called winterizing or system winterization.
In winterizing, the underground exterior components are voided, and a portion of the piping located within the building structure and leading back to the main water line, must also be drained. With present systems this requires access to the residential or commercial dwelling to turn off water flow control valves. Most often, however, because of the high-powered equipment necessary, specially trained personnel are charged with the winterization process. While the actual draining may take only a few minutes of time, 30 minutes to an hour can be spent at each unit due to the necessity of entering the dwelling to accomplish a portion of the work. To drain each prior art sprinkler system the technician must first enter the dwelling and proceed to close a main shut-off valve, and open a first hose bib. The technician then returns outside where a second shut-off valve is closed and a high-pressure air compressor is connected to a second hose bib (36). Upon operation of the compressor the section of feedline located within dwelling (34) is drained of residual water. The technician must then return to the interior of the dwelling to close off the first hose bib. Returning to the outside once again the technician operates the compressor after opening the second shut-off valve. Residual water located in the underground system is forced out of the sprinkler heads. This finally completes the process. It is no wonder that technicians can spend weeks or months trying to get every system flushed in his/her assigned area.
This process presents other problems which must be considered when using prior art devices. First of all, field technicians do not have free access to each building structure. This can manifest as scheduling problems, causing the bulk of winterizations to be performed in evenings and on weekends. Secondly, with the unpredictability of weather, an early freeze could be disastrous. Not only would a number of systems be damaged because they could not be winterized in time, but scheduling would become even more complex trying to winterize systems to prevent further damage.
Until the present invention, there has been no known device which permits technicians to effect all the necessary winterization from a single location outside of the residential or commercial dwelling. One attempt is illustrated in U.S. Pat. No. 4,809,732 to Buehler. This system utilizes a simple air valve to replace a single sprinkler head. With this valve put into place most of the external sprinkler lines can be flushed of water. Feedlines which are not located between sprinkler heads, particularly those which lead back towards the main water source line, would not be drained, and would therefore still present a freezing problem. In addition, the removal, replacement, reattachment of a sprinkler head would take an inordinate amount of time compared to the present invention. Alternatively, there is at least one U.S. patent for a frost proof sillcock (U.S. Pat. No. 4,022,243 to Edwards), but this is not designed for use on an underground sprinkler system. The water pressure and/or water flow generated from this type of device/system would not be sufficient for a proper underground sprinkler system. This is due, in part to the restrictive nature of the valve and piping used. Edwards does teach locating the valve well outside the freeze-zone for outside sillcocks--a field quite different from that of the present invention--but without the teachings of the present invention Edwards' device would not easily permit drainage of an attached sprinkler system. U.S. Pat. No. 4,066,090 to Nakajima et al. also shows a non-freezing valve for use on a sill or water cock. This nature of the Nakajima design is believed to have limitation very similar to that of the Edwards device, particularly since both focus on the same problem.
Another problem, which has added to the already high cost of installing underground sprinkler systems, relates to plumbing. In order to tap into the main water source line a certified plumber must be employed to perform the necessary connection. Most sprinkler installers are not certified plumbers, and therefore are required to subcontract this process. If the plumber needs to spend an inordinate amount of time lining up the feedline, the cost of a sprinkler system can be greatly inflated. The present invention, utilizes means which permit high tolerances for the installation of the necessary valves in new and retrofit systems. This feature can be a tremendous time savings for the plumber, resulting in a significant financial savings to the consumer.
The present invention, in both its apparatus and methods, recognizes and addresses the criteria for winterizing, and water demand and pressure in an underground sprinkler system, and overcomes the limitations perceived by those skilled in the art by presenting a design which, among other aspects, allows for complete control outside of the residential or commercial dwelling. Those skilled in the art of underground sprinkler systems have long been aware of the problems inherent to winterizing sprinkler systems, specifically scheduling difficulties which must be reckoned with, and the unnecessary time spent moving between indoor control valves and outdoor control valves at each location. Unfortunately, the focus has apparently been on designing better sprinkler heads--as shown by U.S. Pat. No. 5,004,157 to Martell--rather than on the valving of the system. Until the present invention, prior art devices have been incapable of quickly and easily winterizing a system, with little or no hassles. All the while the necessary arts and elements for implementing the disclosed invention have existed for sometime. Some of the various patents cited show that while those skilled in the field may have understood that a problem existed, the exact problem was not readily apparent to them. Particularly, with reference to the patent to Buehler, a device is employed which still requires the need for entering the dwelling to close off a main water valve. This only serves to teach away from the direction taken by the inventor of the present invention. In many instances, instead of understanding the true problems, manufacturers and installers have coped with the inherent limitation to the existing devices and methods. There appeared to be a failure to fully understand the problems and impacts of providing a cost and time efficient underground sprinkler system.